Display driving apparatus and display driving method thereof

ABSTRACT

A display driving apparatus including a receiver circuit, a detection circuit and a driving circuit is provided. The receiver circuit receives the video image data at a first rate. The detection circuit is coupled to the receiver circuit. The detection circuit detects whether the video image data is a static image, and determines whether the display driving apparatus enters a power saving mode based on a detecting result. The driving circuit is coupled to the receiver circuit. The driving circuit drives the display panel. In the power saving mode, the receiver circuit continuously receives the video image data at the first rate, and periodically masks a part of the video image data according to the detecting result and outputs an unmasked part of the video image data to the driving circuit. Furthermore, a display driving method adapted for the foregoing display driving apparatus is also provided.

CROSS-REFERENCE TO RELATED APPLICATION

This is a continuation application of and claims the priority benefit ofU.S. application Ser. No. 15/175,047, filed on Jun. 7, 2016, nowallowed. The prior U.S. application Ser. No. 15/175,047 is a divisionalapplication of and claims the priority benefit of U.S. application Ser.No. 13/943,803, filed on Jul. 17, 2013, which claims the prioritybenefit of Taiwan application serial no. 102102688, filed on Jan. 24,2013. The entirety of each of the above-mentioned patent applications ishereby incorporated by reference herein and made a part of thisspecification.

BACKGROUND Technical Field

The invention relates to a driving apparatus and a driving method.Particularly, the invention relates to a display driving apparatus and adisplay driving method thereof.

Related Art

Generally, display driving apparatuses are grouped into display drivingapparatuses containing RAM and RAM-less display driving apparatusesaccording to whether the display driving apparatus has an inbuiltmemory. The inbuilt memory is generally used to temporarily store videoimage data provided by a host, and wait for instruction of a clocksignal to output the stored video image data to a next-stage circuit.

Regarding the RAM-less display driving apparatus, since the inbuiltmemory such as a frame buffer, etc. is not configured in internal of thedisplay driving apparatus, the host has to continuously transmit thevideo image data and vertical and horizontal synchronous signals to thedisplay driving apparatus through a signal transmission interface, so asto facilitate a display panel normally displaying the video images. Thesignal transmission interface used to transmit signals can be a RGB modeinterface or a mobile industry processor interface (MIPI).

Regardless of the type of the signal transmission interface used fortransmitting data, current consumption of the display driving apparatusgenerally includes analog current consumption caused by panel loadingand digital current consumption caused by digital signal action of thesignal transmission interface. Regarding the RAM-less display drivingapparatus, since the host has to continuously write data to the signaltransmission interface, the digital current consumption has a greatinfluence on the whole current consumption of the display drivingapparatus, which is even higher than the analog current consumption insome applications. Therefore, it is an important issue to decrease thepower consumption of the display driving apparatus caused by the digitalcurrent consumption.

SUMMARY

Accordingly, the invention is directed to a display driving apparatus,which is capable of providing a power saving function according to adisplay image, so as to decrease digital current consumption.

The invention provides a display driving method of the aforementioneddisplay driving apparatus, by which a power saving function is providedaccording to a display image, so as to decrease digital currentconsumption.

The invention provides a display driving apparatus, which is used todrive a display panel according to video image data. The display drivingapparatus includes a signal transmission interface, a timing controlcircuit and an image detection circuit. The signal transmissioninterface is configured to receive the video image data and output thevideo image data. The timing control circuit is coupled to the signaltransmission interface, and is configured to receive the video imagedata and drive the display panel based on the video image data. Theimage detection circuit is coupled to the signal transmission interfaceand is configured to receive the video image data. The image detectioncircuit determines whether the video image data is a static image anddetermines whether the display driving apparatus enters a power savingmode based on a determination result. In the power saving mode, thesignal transmission interface masks a part of the video image dataaccording to the determination result, so as not to output the maskedvideo image data to the timing control circuit.

In an embodiment of the invention, the video image data includes aplurality of batches of frame data. The signal transmission interfacemasks a part of the frame data in the video image data in the powersaving mode.

In an embodiment of the invention, the signal transmission interfacefurther outputs a vertical synchronous signal to the timing controlcircuit. In the power saving mode, the masked frame data is arranged atintervals in the frame data in a fixed timing length in response to thevertical synchronous signal.

In an embodiment of the invention, the video image data further includesa plurality of start signals. The start signals are located between theframe data for identifying the frame data.

In an embodiment of the invention, the signal transmission interfaceincludes a receiver circuit. The receiver circuit is used to receive thevideo image data. In the power saving mode, the image detection circuitdisables the receiver circuit according to the start signal.

In an embodiment of the invention, the display driving apparatus furtherincludes a gate driving circuit. The gate driving circuit provides ascan signal to drive the display panel. In the power saving mode, thetiming control circuit outputs a control signal in response to themasked frame data to disable the gate driving circuit.

In an embodiment of the invention, the video image data includes aplurality of batches of frame data, and each batch of the frame dataincludes a plurality of batches of line data. The signal transmissioninterface masks a part of the line data in the frame data in the powersaving mode.

In an embodiment of the invention, the signal transmission interfacefurther outputs a horizontal synchronous signal to the timing controlcircuit. In the power saving mode, the masked line data is arranged atintervals in each batch of the frame data in a fixed timing length inresponse to the horizontal synchronous signal.

In an embodiment of the invention, in a plurality of batches of firstframe data of the frame data, the masked line data includeseven-numbered line data in the line data. In a plurality of batches ofsecond frame data of the frame data, the masked line data includesodd-numbered line data in the line data. The first frame data and thesecond frame data are sequentially arranged at intervals in timing.

In an embodiment of the invention, the video image data further includesa plurality of start signals. The start signals are located between theframe data for identifying the frame data.

In an embodiment of the invention, the display driving apparatus furtherincludes a gate driving circuit. The gate driving circuit provides ascan signal to drive the display panel during a period that the part ofline data is masked in the power saving mode.

The invention provides a display driving method, which is used to drivea display panel according to video image data. The display drivingmethod includes following steps. The video image data is received. It isdetermined whether the video image data is a static image. It isdetermined whether the display driving apparatus enters a power savingmode based on a determination result. In the power saving mode, a partof the video image data is masked according to the determination result.The display panel is driven according to the video image data.

In an embodiment of the invention, the video image data includes aplurality of batches of frame data. The step of masking a part of thevideo image data includes masking a part of the frame data in the videoimage data.

In an embodiment of the invention, the display driving method furtherincludes driving the display panel according to a vertical synchronoussignal. In the power saving mode, the masked frame data is arranged atintervals in the frame data in a fixed timing length in response to thevertical synchronous signal.

In an embodiment of the invention, the video image data further includesa plurality of start signals. The start signals are located between theframe data for identifying the frame data.

In an embodiment of the invention, the video image data further includesreceiving the video image data by using a receiver circuit. The videoimage data further includes disabling the receiver circuit according tothe start signal in the power saving mode.

In an embodiment of the invention, the display driving method furtherincludes following steps. A gate driving circuit is used to a scansignal to drive the display panel. In the power saving mode, a controlsignal is output in response to the masked frame data to disable thegate driving circuit.

In an embodiment of the invention, the video image data includes aplurality of batches of frame data, and each batch of the frame dataincludes a plurality of batches of line data. In the step of masking apart of the video image data, a part of the line data in the frame datais masked.

In an embodiment of the invention, the display driving method furtherincludes driving the display panel according to a horizontal synchronoussignal. In the power saving mode, the masked line data is arranged atintervals in each batch of the frame data in a fixed timing length inresponse to the horizontal synchronous signal.

In an embodiment of the invention, in a plurality of batches of firstframe data of the frame data, the masked line data includeseven-numbered line data in the line data. In a plurality of batches ofsecond frame data of the frame data, the masked line data includesodd-numbered line data in the line data. The first frame data and thesecond frame data are arranged at intervals in timing.

In an embodiment of the invention, the video image data further includesa plurality of start signals. The start signals are located between theframe data for identifying the frame data.

In an embodiment of the invention, the display driving method furtherincludes using a gate driving circuit to provide a scan signal to drivethe display panel during a period that the part of line data is maskedin the power saving mode.

According to the above descriptions, in the exemplary embodiment of theinvention, the display driving apparatus has the power saving mode todecrease digital current consumption. In the power saving mode, thesignal transmission interface masks a part of the video image data anddoes not output the masked video image data to the timing controlcircuit, so as to achieve a power saving effect.

In order to make the aforementioned and other features and advantages ofthe invention comprehensible, several exemplary embodiments accompaniedwith figures are described in detail below.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a furtherunderstanding of the invention, and are incorporated in and constitute apart of this specification. The drawings illustrate embodiments of theinvention and, together with the description, serve to explain theprinciples of the invention.

FIG. 1 is a schematic diagram of a display driving apparatus accordingto an embodiment of the invention.

FIG. 2 is a flowchart illustrating a method for determining whether apower saving mode of a display driving apparatus is activated accordingto an embodiment of the invention.

FIG. 3 is a waveform diagram of various signals of a display drivingapparatus according to an embodiment of the invention.

FIG. 4 is a waveform diagram of various signals of a display drivingapparatus according to another embodiment of the invention.

FIG. 5 is a waveform diagram of various signals of a display drivingapparatus according to another embodiment of the invention.

FIG. 6 is a schematic diagram of a display driving apparatus accordingto another embodiment of the invention.

FIG. 7 is a flowchart illustrating a display driving method according toan embodiment of the invention.

DETAILED DESCRIPTION OF DISCLOSED EMBODIMENTS

FIG. 1 is a schematic diagram of a display driving apparatus accordingto an embodiment of the invention. Referring to FIG. 1, the displaydriving apparatus 100 of the present embodiment receives video imagedata SD from a host 200, and drives a display panel (not shown)according to the video image data SD. In the present embodiment, inorder to achieve a power saving effect, the display driving apparatus100 can modulate a display behavior including determining whether thevideo image data SD is a static image, so as to determine whether toenter a power saving mode without adjusting a design structure of thehost 200.

In detail, the display driving apparatus 100 includes a signaltransmission interface 110, a timing control circuit 120, an imagedetection circuit 130, a source driving circuit 140 and a gate drivingcircuit 150. In the present embodiment, the signal transmissioninterface 110 includes a receiver circuit 112, and receives the videoimage data SD, and outputs the video image data SD, a horizontalsynchronous signal HS and a vertical synchronous signal VS to thecontrol circuit 120 and the image detection circuit 130. The signaltransmission interface 110 can be a RGB mode interface, a MIPI modeinterface or other signal transmission interface, which is not limitedby the invention. In the embodiment of the MIPI mode interface, thereceiver circuit 112 is, for example, a DPHY circuit complied with theMIPI mode interface.

In the present embodiment, the timing control circuit 120 is coupled tothe signal transmission interface 110, and receives the video image dataSD, the horizontal synchronous signal HS and the vertical synchronoussignal VS. Moreover, the timing control circuit 120 transmits the videoimage data SD, the horizontal synchronous signal HS and the verticalsynchronous signal VS to the source driving circuit 140 and the gatedriving circuit 150 to facilitate the source driving circuit 140 and thegate driving circuit 150 accordingly driving the display panel. Itshould be noticed that in order to achieve the power saving effect, inthe power saving mode, a part of frame data or line data in the videoimage data SD transmitted to the source driving circuit 140 is probablymasked by the timing control circuit 120, and the masked frame data orline data is not output to the source driving circuit 140 to decreasethe digital current consumption.

In the present embodiment, the image detection circuit 130 is coupledbetween the signal transmission interface 110 and the timing controlcircuit 120, and receives the video image data SD. In the presentembodiment, the image detection circuit 130 determines whether the videoimage data transmitted from the host 200 is a static image anddetermines whether the display driving apparatus 100 enters the powersaving mode based on a determination result. The method for the imagedetection circuit 130 determining whether the display driving apparatus100 enters the power saving mode is described below.

FIG. 2 is a flowchart illustrating a method for determining whether thepower saving mode of the display driving apparatus is activatedaccording to an embodiment of the invention. Referring to FIG. 1 andFIG. 2, the method includes following steps. First, in step S200, theimage detection circuit 130 receives the video image data SD output bythe signal transmission interface 110. Then, in step S210, the imagedetection circuit 130 determines whether the video image data SD is astatic image, and the determination method thereof includes comparing adifference between image content characteristics of two images accordingto the image content characteristic such as image resolution, imagebrightness, image spectrum distribution, image difference, imagecorrelation, image number of colors, image refresh rate or display mode,etc. based on frame, so as to determine whether the current video imagedata SD is the static image.

Therefore, if it is determined in the step S210 that the received videoimage data SD is the static image, in step S220, the image detectioncircuit 130 controls the display driving apparatus 100 to enter thepower saving mode. In the power saving mode, the signal transmissioninterface 110 masks a part of the video image data SD according to thedetermination result, so that the image detection circuit 130 does notoutput the masked video image data to the timing control circuit 120. Onthe other hand, if it is determined in the step S210 that the receivedvideo image data SD is a dynamic image, in step S230, the imagedetection circuit 130 controls the display driving apparatus 100 toenter a non-power saving mode. In the step S230, the non-power savingmode is, for example, a normal operation mode, and in such operationmode, the signal transmission interface 110 does not mask the videoimage data SD, but directly outputs the video image data SD to thetiming control circuit 120 through the image detection circuit 130, soas to implement image display.

Then, in step S240, the signal transmission interface 110 transmits thevideo image data SD to the timing control circuit 120 through the imagedetection circuit 130. The video image data SD can be the video imagedata SD of the power saving mode with a part of data therein beingmasked, or can be the video image data SD of the non-power saving modewithout data being masked.

In the exemplary embodiment of the invention, when the display drivingapparatus 100 enters the power saving mode, the method of power savingoperation at least includes masking a part of frame data in the videoimage data SD, masking a part of line data in the frame data, ordirectly disabling the receiver circuit 112 in the signal transmissioninterface 110. Implementations of the power saving operation arerespectively described below.

FIG. 3 is a waveform diagram of various signals of a display drivingapparatus according to an embodiment of the invention. Referring to FIG.1 and FIG. 3, the signal waveforms of FIG. 3 are sequentially signalwaveforms of the video image data SD, the vertical synchronous signalVS, video image data SD′ output to the source driving circuit 140 and agate control signal SG output to the gate driving circuit 150 from topto bottom.

In the present embodiment, taking the MIPI mode interface as an example,the video image data SD is, for example, transmitted to the signaltransmission interface 110 through a DP/NP data lane, which has acharacteristic of high speed data transfer. In such example, the videoimage data SD can be approximately divided into a plurality of batchesof frame data F1-FN based on frame. In the power saving mode, after thesignal transmission interface 110 receives the video image data SD, thesignal transmission interface 110 masks a part of the frame data in thevideo image data SD. In the present embodiment, the signal transmissioninterface 110 masks the frame data F3 and F6, and then transmits thevideo image data SD to the timing control circuit 120. Therefore, inview of the video image data SD′, the masked frame data F3 and F6 arearranged at intervals in the frame data F1-FN in a fixed timing lengthin response to the vertical synchronous signal VS, where the timinglength, for example, refers to a timing length of two frame periods.Namely, after the signal transmission interface 110 sequentially outputsthe frame data F1 and F2 to the timing control circuit 120, the signaltransmission interface 110 does not output the frame data F3 to thetiming control circuit 120, i.e. masks the frame data F3. Then, thesignal transmission interface 110 sequentially outputs the frame data F4and F5 to the timing control circuit 120, and does not output the framedata F6 to the timing control circuit 120, i.e. masks the frame data F6.In FIG. 3, the video image data SD′ is indicated as “OFF” at placescorresponding to the frame data F3 and F6, which represents that theframe data F3 and F6 are masked. Therefore, according to such frame datamasking method, in such example, an operation frequency of the displaypanel can be decreased by ⅓ to achieve the power saving effect. Itshould be noticed that in the present embodiment, the number of batchesand timing positions of the masked frame data in the video image dataSD′ can be determined according to an actual design requirement, whichis not limited by the invention.

It should be noticed that in the power saving mode, in response to themasked frame data F3 and F6, the timing control circuit 120 outputs thegate control signal SG of a low level VGL to disable the gate drivingcircuit 150 at the corresponding timing. In FIG. 3, the gate controlsignal SG is indicated as “VGL” at places corresponding to the framedata F3 and F6, which represents that the gate driving circuit 150 isdisabled. In other words, the gate driving circuit 150 performs thenormal scan driving operation to the display panel only in a timingperiod without the masked frame data.

In the embodiment of FIG. 3, the display driving apparatus 100implements the power saving operation by masking a part of the framedata in the video image data SD, though the invention is not limitedthereto. In other embodiment, the image detection circuit 130 can alsodirectly disable the receiver circuit 112 in the signal transmissioninterface 110, such that the receiver circuit 112 does not receive theframe data, so as to achieve an effect similar to the frame data maskingeffect.

FIG. 4 is a waveform diagram of various signals of a display drivingapparatus according to another embodiment of the invention. Referring toFIG. 1 and FIG. 4, the signal waveforms of the video image data SD, thevertical synchronous signal VS, the video image data SD′ and the gatecontrol signal SG in FIG. 4 are similar as that drawn in FIG. 3, thougha signal waveform of a control signal PHY used for controlling a workingstate of the receiver circuit 112 is further disclosed in FIG. 4.

In detail, in the present embodiment, the video image data SD includes aplurality of start signals SoT. The start signals SoT are locatedbetween the frame data F1-FN for identifying the frame data F1-FN. Whenthe signal transmission interface 110 receives the start signal SoT, itrepresents that the frame data after the received start signal SoT isdifferent to the other frame data before the received start signal SoT.Namely, the two batches of frame data before and after the start signalSoT represent frame data of different frame periods.

Therefore, in the power saving mode, the image detection circuit 130disables the receiver circuit 112 according to the start signal SoT. Forexample, according to the determination result, if the timing controlcircuit 120 is set to be not to output the frame data F3 during theframe period of the frame data F3, when the image detection circuit 130receives the start signal SoT located before the frame data F3, theimage detection circuit 130 directly disables the receiver circuit 112(indicated as “OFF” in FIG. 4) by using the low level control signalPHY, such that the receiver circuit 112 does not receive the frame dataF3. Until the image detection circuit 130 receives the start signal SoTlocated after the frame data F3, the image detection circuit 130re-enables the receiver circuit 112. In view of the video image dataSD′, since the receiver circuit 112 does not receive the frame data F3,the timing control circuit 120 and the source driving circuit 140 do notreceive the frame data F3 either. Therefore, by directly disabling thereceiver circuit 112, the effect of masking the frame data F3 in thevideo image data SD′ is also achieved. Moreover, the method of maskingthe frame data F6 or other frame data by disabling the receiver circuit112 can be deduced according to the aforementioned instructions.

In the embodiments of FIG. 3 and FIG. 4, the display driving apparatus100 implements the power saving operation by masking a part of the framedata in the video image data SD or directly disabling the receivercircuit 112, though the invention is not limited thereto. In otherembodiment, the image detection circuit 130 can also mask a part of theline data in each batch of the frame data to achieve the power savingeffect.

FIG. 5 is a waveform diagram of various signals of a display drivingapparatus according to another embodiment of the invention. Referring toFIG. 1 and FIG. 5, the signal waveforms of FIG. 5 are sequentiallysignal waveforms of the video image data SD, the horizontal synchronoussignal HS, the vertical synchronous signal VS, video image data SD′output to the source driving circuit 140 and the gate control signal SGoutput to the gate driving circuit 150 from top to bottom.

In the present embodiment, each batch of frame data includes a pluralityof batches of line data. In the power saving mode, the image detectioncircuit 130 masks a part of the line data in each batch of frame data todecrease the digital current consumption. In such example, the maskedline data is arranged at intervals in each batch of the frame data in afixed timing length in response to the horizontal synchronous signal HS,where the timing length, for example, refers to a timing length of onebatch of line data. Taking the frame data F1 and F2 as an example, theframe data F1 and F2 respectively includes line data L1-LM. In the framedata F1, the image detection circuit 130 masks the even-numbered linedata L2, L4, . . . , LM, and in the line data L2, L4, . . . , LM, aspace between any batch of the line data and a next batch of the linedata is a timing length of one line data. Similarly, in the frame dataF2, the image detection circuit 130 masks the odd-numbered line data L1,L3, L5, . . . , LM−1 (not shown), and in the line data L1, L3, L5, . . ., LM−1, a space between any batch of the line data and a next batch ofthe line data is also a timing length of one line data. Therefore, theframe data F3-FN can be deduced according to the above masking manner,and timing positions and the arrangement method of the masked line dataare not repeated.

In overall, in the present embodiment, in a plurality of batches offirst frame data F1, F3, F5, . . . , FN−1 of the frame data F1-FN, themasked line data includes even-numbered line data L2, L4, . . . , LM inthe line data L1-LM. In a plurality of batches of second frame data F2,F4, . . . , FN of the frame data F1-FN, the masked line data includesodd-numbered line data in the line data L1-LM, where the first framedata F1, F3, F5, . . . , FN−1 and the second frame data F2, F4, . . . ,FN are arranged at intervals in timing.

It should be noticed that in the present embodiment, the timing positionand the arrangement method of the masked line data are only used as anexample, and the invention is not limited thereto. Moreover, it shouldbe noticed that in the power saving mode, during the period that a partof the line data is masked, the gate driving circuit 150 is still in thenormal scan driving state, and continuously provide the scan signal todrive the display panel.

In the embodiment of FIG. 1, the display driving apparatus 100 is aRAM-less display driving apparatus, namely, the inbuilt memory such as aframe buffer, etc. is not configured therein. However, the displaydriving method of the invention is not limited to be applied to theRAM-less display driving apparatus, which can also be applied to thedisplay driving apparatus containing RAM.

FIG. 6 is a schematic diagram of a display driving apparatus accordingto another embodiment of the invention. Referring to FIG. 1 and FIG. 6,the display driving apparatus 600 of the present embodiment is similarto the display driving apparatus 100 of FIG. 1, and a main differencethere between is that the display driving apparatus 600 further includesa clock generation circuit 660 and a memory circuit 670. In the presentembodiment, the memory circuit 670 is used to temporarily store thevideo image data SD provided by the host 200, and wait for instructionof the clock generation circuit 660 to output the stored video imagedata SD to the clock control circuit 620. Moreover, the clock generationcircuit 660 also generates the horizontal synchronous signal HS and thevertical synchronous signal VS to the timing control circuit 620 tofacilitate the timing control circuit 620 driving the display panel.

FIG. 7 is a flowchart illustrating a display driving method according toan embodiment of the invention. Referring to FIG. 1 and FIG. 7, thedisplay driving method of the present embodiment is, for example,adapted to the display driving apparatuses 100 and 600 of FIG. 1 andFIG. 6, and includes following steps.

First, in step S700, the display driving apparatus 100 receives thevideo image data SD. Then, in step S710, the image detection circuit 130determines whether the video image data SD is a static image. Then, instep S720, the image detection circuit 130 determines whether thedisplay driving apparatus 100 enters the power saving mode according tothe determination result. Then, in step S730, in the power saving mode,the image detection circuit 130 masks a part of the video image data SDaccording to the determination result. In step S740, the display drivingapparatus 100 drives the display panel according to the video image dataSD.

Moreover, since enough instructions and recommendations of the displaydriving method of the present embodiment can be learned from thedescriptions of the embodiments of FIG. 1 to FIG. 6, detaileddescription thereof is not repeated.

In summary, in the exemplary embodiments of the invention, the displaydriving apparatus has the power saving mode to decrease digital currentconsumption. In the power saving mode, the signal transmission interfacemasks a part of the video image data and does not output the maskedvideo image data to the timing control circuit, so as to achieve a powersaving effect. Moreover, the display driving apparatus can also disablethe receiver circuit of the signal transmission interface to stop thereceiver circuit receiving the frame data, so as to achieve an effectsimilar to that of masking the frame data.

It will be apparent to those skilled in the art that variousmodifications and variations can be made to the structure of theinvention without departing from the scope or spirit of the invention.In view of the foregoing, it is intended that the invention covermodifications and variations of this invention provided they fall withinthe scope of the following claims and their equivalents.

What is claimed is:
 1. A display driving apparatus, adapted to drive adisplay panel according to video image data, the display drivingapparatus comprising: a receiver circuit, configured to receive thevideo image data continuously provided by an external host at a firstrate in a normal operation mode; a detection circuit, coupled to thereceiver circuit, and configured to receive the video image dataoutputted by the receiver circuit, detect whether the video image datais a static image, and determine whether the display driving apparatusenters a power saving mode based on a detecting result; and a drivingcircuit, coupled to the receiver circuit, and configured to drive thedisplay panel, wherein in the power saving mode, the receiver circuitcontinuously receives the video image data continuously provided by theexternal host at the first rate, and periodically masks a part of thevideo image data according to the detecting result and outputs anunmasked part of the video image data to the driving circuit, whereinthe display driving apparatus is a RAM-less display driving apparatuswithout frame buffers.
 2. The display driving apparatus as claimed inclaim 1, wherein the video image data comprises a plurality of framedata, and the receiver circuit masks a part of the plurality of framedata in the video image data in the power saving mode.
 3. The displaydriving apparatus as claimed in claim 2, wherein the video image datafurther comprises a plurality of start signals, and the plurality ofstart signals are located between the plurality of frame data foridentifying the plurality of frame data.
 4. The display drivingapparatus as claimed in claim 3, wherein in the power saving mode, thedetection circuit disables the receiver circuit according to theplurality of start signals.
 5. The display driving apparatus as claimedin claim 2, further comprising a control circuit for receiving the videoimage data from the receiver circuit, and controlling the drivingcircuit based on the video image data, so that the driving circuitprovides a scan signal to drive the display panel, wherein in the powersaving mode, the control circuit outputs a control signal in response tothe masked part of the plurality of frame data to disable the drivingcircuit.
 6. The display driving apparatus as claimed in claim 1, whereinthe video image data comprises a plurality of frame data, and each ofthe plurality of frame data comprises a plurality of line data, and thereceiver circuit masks a part of the plurality of line data in theplurality of frame data in the power saving mode.
 7. The display drivingapparatus as claimed in claim 6, wherein the video image data furthercomprises a plurality of start signals, and the plurality of startsignals are located between the plurality of frame data for identifyingthe plurality of frame data.
 8. The display driving apparatus as claimedin claim 6, wherein the driving circuit provides a scan signal to drivethe display panel during a period that the part of the plurality of linedata is masked in the power saving mode.
 9. A display driving method,adapted to a display driving apparatus for driving a display panelaccording to video image data, and the display driving methodcomprising: receiving the video image data continuously provided by anexternal host at a first rate in a normal operation mode; detectingwhether the video image data received from the external host is a staticimage; determining whether the display driving apparatus enters a powersaving mode based on a detecting result; receiving the video image datacontinuously provided by the external host at the first rate in thepower saving mode; periodically masking a part of the video image dataaccording to the detecting result in the power saving mode andoutputting an unmasked part of the video image data; and driving thedisplay panel according to the unmasked part of the video image data,wherein the display driving apparatus is a RAM-less display drivingapparatus without frame buffers.
 10. The display driving method asclaimed in claim 9, wherein the video image data comprises a pluralityof frame data, and the step of periodically masking a part of the videoimage data comprises masking a part of the plurality of frame data inthe video image data.
 11. The display driving method as claimed in claim10, wherein the video image data further comprises a plurality of startsignals, and the plurality of start signals are located between theplurality of frame data for identifying the plurality of frame data. 12.The display driving method as claimed in claim 11, wherein a receivercircuit is used to receive the video image data, and the display drivingmethod further comprises: disabling the receiver circuit according tothe plurality of start signals in the power saving mode.
 13. The displaydriving method as claimed in claim 10, further comprising: providing ascan signal by a driving circuit, so as to drive the display panel; andoutputting a control signal in response to the masked part of theplurality of frame data to disable the driving circuit in the powersaving mode.
 14. The display driving method as claimed in claim 9,wherein the video image data comprises a plurality of frame data, eachof the plurality of frame data comprises a plurality of line data, andthe step of periodically masking the part of the video image datacomprises masking a part of the plurality of line data in the pluralityof frame data.
 15. The display driving method as claimed in claim 14,wherein the video image data further comprises a plurality of startsignals, and the plurality of start signals are located between theplurality of frame data for identifying the plurality of frame data. 16.The display driving method as claimed in claim 14, further comprising:providing a scan signal to drive the display panel by a driving circuitduring a period that the part of the plurality of line data is masked inthe power saving mode.